Fabric feeding mechanism for sewing machines



. Jan. 25, 1938. N. v. CHRISTENSEN ET AL 2,105,517

FABRIC FEEDING MECHANISM FOR SEWING MACHINES Filed June 5, 1955 4 sheets-sheet 1 H61 I X .50 5 51v z i 5 1 f); 0

NormanVL'hnsifcnsm,

Charles K 1171117371,

7-! ram lLaVzsconia,

Jan. 25, 1938. N. v. CHRISTENSEN ET AL 0 7 FABRIC FEEDING MECHANISM FOR SEWING MACHINES Filed June 5, 1935 I 4 Sheets-Sheet 2 k 1NVENTOR$= mrman'lfflhrisim W1 I Q; Chart 1? Rig/ 301 TTORNEYS.

Jan. 25, 1938- N. v. CHRISTENSEN ET AL 2,106,517

FABRIC FEEDING MECHANISM FOR SEWING MACHINES Filed June 5, 1935 4 Sheets-Sheet 5 PIC-71E INVENTORSI mrmanyflhrishnscn charms FHuZmL,

5a L'Larenca (I- Smiih 5:.

y BY Harold LILzfl/ssconia,

Jan. 25, 1938. N. v. CHRISTENSEN z-rr AL 2,106,517

FABRIC FEEDING MECHANISM FOR SEWING MACHINES Filed June 5; 1935 4 Sheets-Sheet 4 NVENTOR5= L'harlas 'FI' Rahal? WITNESSES:

Ciarenca 6.5111351 13!. 1 y 011d JLa'lsoo 5a,

ATTORNEYS.

Patented Jan. 25, 1938 UNITED STATES PATENT orrica FABRIC FEEDING MECHANISM FOR SEW- ING MACHINES Application June 5, 1935, Serial No. 25,094

36 Claims. (01. 112-212) This invention relates to mechanism adapted to progress fabric along the work support of a sewing machine for seaming.

The fabric feeding elements heretofore generally used in sewing machines are of two types, to wit: the intermittent surface contact type exemplified by the four motion feed dog; and the constant single line contact type exemplified by the roller. While the feed dog is advantageous in that it makes substantial surface contact with the fabric, its constant pounding at high speeds may result in marring the surface of the fabric. The roller feed is notfully effective to perform difficult feeding because of its limited contact with the fabric.

Our invention is more particularly intended to overcome the foregoing drawbacks. This objective we attain, as hereinafter more fully disclosed, through provision ofa feed element in the form of a flexible horizontal chain belt having links with serrated fabric engaging edges, and aligned with the needle or needles in the direction of feed, the needle or needles being thereby left free of obstructionand hence readilyaccessible for threading.

Another object of our invention is to incorporate as a component part of feed mechanism characterized as above, a presser foot capable of up and down movement in coordination with the feed belt to facilitate over-riding of cross seams and the like in the fabric.

A further object of our invention is to provide for the support of the belt and the presser foot y the drawings, wherein Fig. I is a fragmentary view showing, in part, the rear elevation of a sewing machine embodying our novel feed mechanism.

Fig. II is a fragmentary sectional view taken as indicated by the arrows IIII in Fig. I.

Fig. H1 is a view looking as indicated by the arrows III-III in Fig. II, with'certain parts broken away to expose important details which would otherwise be hidden.

Fig. IV is a view corresponding to Fig. II with the presser foot element lifted.

Fig. V is a plan sectional view taken as indicated by the arrows V-'V in Fig. IV.

Fig. V1 is a plan sectional view taken as indicated by the arrows VI-VI in Fig. VII.

Fig. VII is a fragmentary view in elevation looking as indicated by the arrows VII-VII in Fig. I.

Fig. VIII is a cross sectional view taken as indicated by the arrows VIIIVIII in Fig. II; and

Fig. IX is a fragmentary perspective view of the feed chain belt.

As herein shown, the feed mechanism of our invention comprises a flexible element in the form of a relatively wide, horizontal, endless chain belt I adapted in this instance to yieldingly engage the fabric F being sewed in the machine from above. The chain belt I is intermittently moved, by means later on described, in the direction indicated by the arrow in Fig. IV to progress the fabric along the work support 2 of the machine relative to the'three staggeringly-arranged needles 3, the illustrated machine being of a type designed for sewing triple-stitched, double-lap, felled seams such as illustrated at S in Fig. III. As shown, the chain belt I is allocated in the rear of the needles 3 so that ready access may be had to the latter for threading, and is composed of stamped metal links with serrated or toothed edges to take effective hold upon the fabric. The intermediate links la of the chain I (Fig. IX) are suitably configured to mesh with the teeth of spaced drive and idler sprocketwheels 4 and 5 about which said chain is trained; while the outermost chain links lb lap the sides of the sprockets and thereby hold the. chain against lateral displacement. The idler sprocket 5 revolves freely about a non-rotating axis pin 6 which extends crosswise of one end of a journal member 1 fulcrumed for up and down rocking movement on the shaft 8 where to the drive sprocket wheel 4 is secured, the spaced side portions or cheeks 1a of said journal member being integrally connected by a transverse bridging web lb above the adjustment, the axis pin 6 is clamped against the.

possibility of accidental rotation by a clamp screw be which engages axially into the reduced concentric end portion thereof. But the chain is never so taut as to prevent it from yieldingupwardly between the sprocket wheels "to" a slight extent when required by conditions of )usage.

From Figs. V and VII it willbe observed that the ends of theaxisor shaft 9 of the sprocket wheel 4 are engaged in bearings 9a on laterallyspaced rearward extremities 9b of a horizontal carrier member 9, wh lch, as shown, has the form of a double yoke frame whereof the opposite side portions are integrally connected bya transverse web 90. Supported between the forward extremities 9d of the horizontal carrier member 9 in the rear of the chain l and aligned therewith in the direction of feed is a presser foot 10 having upward lugs Illa pivotally connected to the ends of said extremities by screw studs H, and having its front end inclined upwardly as at lllb so that it can readily over-ride cross seams and the like in the fabric F. As shown, the horizontal portion of the presser foot I0 is provided with longitudinally-elongate apertures l2 for passage of the seaming needles 3 of the machine. In the illustrated instance the underface of the presser foot I!) is recessed lengthwise as at lllc to clear the double lap felled seam S of the fabric in the manner clearly shown in Fig. III.

Approximately midway between the bearings 9a and the pivots Illa of the presser foot element ill, the horizontal carrier member 9 has pivot connections l3 at opposite sides with the of the head I! is an arm l8 which extends outward through an, opening in one side of said head and engages between a pair of vertical guide plates I9 made fast to the head by screws 2ll,'see Figs. II and III, the presser bar being thus held against rotation incident to its axial movements. Pivotally engaging the sprocket shaft 8 in the intervals between the cheeks Ia of the journal member I and the rearward extremities 9b of the horizontal carrier member 9, are the extremities 2la of a vertical guide member 2| which also has the form of a yoke with a cross web 2") integrally uniting said extremities at the top. As shown, the guide members 2| is slotted centrally of its top as at 2lc (Figs. III and VI) to engage an integral rearwardly extending horizontal tongue Nb of the shank member H, which tongue in turn engages the vertical slot 22a in an angle bracket 22 secured to the head I! of the sewing machine by screws 23. Obviously, by virtue of the arrangement just described, the: feed chain belt I is positively maintained aligned with the needles 3 of the machine in the direction of feed.

In order to yieldingly hold down the free end of the journal member 1, means have been provided which include a vertical sleeve 25 with a closed spherical bottom end and a projecting axial tip 250. which engage an apertured seat 26 in the top of the cross web "lb 'of said member. Extending part way into the hollow of the sleeve 25 from above is the diametrically reduced pilot extension 21a of an adjusting screw 21 which is adjustable in an angle bracket 28 secured to the projecting end of the arm l8 on the presser bar l5 and which is fixable in adjusted positions by a clamp nut 29. By adjusting the screw 21 it is possible to regulate the force of a helical spring 30 which surrounds the pilot extension of said screw, and which, at its lower end bears upon the bottom of the hollow in the sleeve 25,

(Fig. II) the pressure of the spring being communicated through the sleeve to the journal member I.

Also adjustable in the angle bracket 28 is another adjusting screw 3| with a diametricallyreduced pilot extension am which reaches part way down into a vertical sleeve 32 and subject to a helical compression spring 33. The bottom end of the sleeve 32 is clevised as shown at 32a for connection by a pivot screw 34 with the end of the longer of the two rearward extremities 9b of the horizontal carrier member 9, see Figs. III, V, VI and VII. The function of the spring 33 is to oppose, to a certain extent, the pressure of the presser bar l5 upon the presser foot l0 and thereby correspondingly relieve the latter so that cross seams in the fabric F may more readily pass thereunder. A jamb nut 35 serves to secure the screw 3| in adjusted positions.

The rocking movement of the belt I and the rocking movement of the presser foot II) are both of special utility when a cross seam passes under the presser foot and then under the feed belt as it enables this to be accomplished with very little rise or fall of the presser bar. This is desirable in that there is less flexure of the presser bar spring and therefore less danger of its breaking through crystallization. Moreover, in partaking of rocking movement to accommodate progres sion of a cross seam beneath it, the feed belt remains in contact with the fabric not only at the cross seam but also with the fabric either in the front or in the rear of the cross seam according to the position of the latter and the direction of rocking. Furthermore, the feed belt is capable of yielding upwardly between its supporting wheels. Accordingly, effective contact over an extensive area is maintained with the fabric under all conditions.

In order to prevent the driven portion of the feed chain I from coming into direct contact with the work support 2 of the sewing machine at any time, a stop means has been provided to limit the downward movement thereof. As shown in Figs. III and VII this stop means comprises a drop link 36 which pivots on a screw.

31 at one side of the angle bracket 22, and which, at its lower end, has a vertical slot 31a to cooperate with a stud 38 projecting laterally from the guide member 2!. With no fabric beneath the belt I, the-pin 38 rests in the bottom of the slot 31a of the link 36 and thereby holds the guide member 20 at an elevation such that there is a slight clearance beneath the belt I at the sprocket wheel 4. The extent of up and down swinging movement of the journal member I about the axis 8 of the drive sprocket 4 is limited through cooperation of a .stud screw 40 at one 'ent No. 1,758,349 of .May 13, 1930, to Joseph Berger et-al., may be utilized in the sewing machine for raising the presser bar to lift the feed belt I and the presser foot high above the amass? work support 2 when required. With initiation in the upward movement of the presser bar by means such as just referred to, the presser foot H3 rises ahead of the chain l until the extremities 9d of the carrier member 9 engage the shoulders Md on the extremities Ma oi the shank member id, as shown in Fig. IV. Then, as the upward movement of the presser bar--55 con tinues, the journal member 1 will pivot on the sprocket wheel axis 6 until the stud 69 engages the edge of the enlarged hole M in the guide 1 member 29, whereafter the feed chain will be bodily lifted entirely clear of the work support.

1 Any suitable means may be provided for mov-- ing the belt as required to progress the fabric along the work plate. This means may for ex ample comprise a bevel gear wheellfisecured to one end of the drive sprocket'shaft 3, and a meshing companion sprocket wheel 53 at the bottom end of a vertical shaft Ml havin journal support in a bearirfg at the end of a lateral arm projection Zld of the guide member 2i. As shown in Figs. I and II the vertical shaft 56 telescopically engages a sleeve 35, which,

at its upper end, has a universal connection db with an aligned vertical shaft ll having journal support in a fixed bearing d8. A key dda (Fig.

II) secured to the upper end of theshait ts engages a longitudinalslot 351; in the sleeve 45 to prevent relative rotationbetweensaid shaft and sleeve while permitting up and down movements of the feed belt I during. the operationof the, sewing machine as well as during lift ing of the belt by raising of the presser bar-v ihe vertical shaft 137 is intermittently roi5. tated through the medium of a roller clutch (not illustrated) concealed in a hollow cylinder db at the top of the head ll, said clutch being connected by a horizontal link Edwith a rocker arm 5i fulcrumed at 52 to the side of the machine frame. The rocker arm Si is in-turn actuated y from an eccentric 53 on a continuouslyrotating shaft 541 which receives its motion'from the drive H mechanism of the sewing machine. 7

From the foregoing it will be seenthat the feed mechanism of our invention is simple in construction since both the'feed chain 8 and the presser foot W are carried by a single yielding element-in this instance, the spring influenced presser bar le -and both accordingly urged' downward with capacity to adaptjthemselves positionally to surface variations of the fabric passing beneath them.

Having thus described our invention, we claim.

1. Feeding mechanism for sewing machines comprising an endless belt; yielding means for holding the belt with capacity for angular movementpin pressure contact with the fabric being seamed in the sewing machine; and means for driving the belt to progress the fabric.

2. Feeding mechanism for sewing machines comprising an endless belt; yielding means operative from above for holding the belt with ca pacity for angular movement in pressurecon tact with the upper side of the fabric being seemed in the machine; and means for-driving the belt.

3. Feeding mechanism for sewing machines comprising an endless chain belt with links having serrated edges to engage the fabric being. seamed in the machine; means for maintainingthe belt with capacity for angular movement,.

, in yielding pressure contact with the fabric; and

means for driving the belt.

4. Feeding mechanism for sewingmachinea comprising an endless chain belt; means for driving the belt to progress the fabric; means crea'ting downward pressure to hold the belt in contact with the fabric being seamed; and means permitting said belt to rock, thereby assisting progression of cross seams under the'belt.

5.-Feeding mechanism for sewing machines comprising. spaced sprocket wheels; an endless chain belt composed "of intermediate and outer links with serrated edges to engage the fabric being seamed in the machine, the intermediate -links of the chain belt being notched for engagement by the teeth of the sprocket wheels and the e links lapping the outer sides of the sprockets to prevent displacement of the belt; means for maintaining the belt yieldingly in contact withthe fabric; and mcans'for driving the belt.

6.! Feeding mechanism for sewing machines cbmprislng an endless belt in line with the needle of the machine in the direction of feed; means for maintaining the belt with capacity for angular movement. yieldingly in surface contact with the fabric being seamed in the machine; and means for driving the belt.

7. Feeding mechanism for sewing machines comprising an endless belt in line with, and disposed in the rear of theseaming needle of the machine inthe direction of feed; means for maintaininglthe belt with capacity for angular :movement, yieldingly in surface contact with the fabric'beingseanied in the machine; and means for driving. the belt.

'8. Feeding. mechanisrn' for sewing machines comprising an endless belt-adapted to engage the fabric being-seamed in the machine; means for supporting the belt in yielding contact with the fabric with capacity for direct vertical movemerit as well as for up and down rocking movemer t; and means for driving the belt. 1 9.. Feeding mechanism for sewing machines comprising an endless chain. belt adapted to engage the fabric being seamed in the machine and having capacity for angular movement; sprocket wheels around which said belt is trained, said, sprocket wheels being so spaced as to maintain the sur'f ace oi the chain belt in effective contact with the work being fed'while .yet permitting aslight. yielding of the belt between the sprocket'wheels-when' required by conditions of usage.

l0.- Feeding mechanism for sewing machines the fabric being seemed in the machine; supporting means for the belt in operative conneccomprising an endless feed belt and a presser foot; means for. maintaining both the belt and the presser foot in yielding pressure contact with the fabricrz-beihg seamed; and means for permitting the belt and the presser foot to rock, fi ch in relation to the other,'to facilitate the passage of a i cross seam.

-.comprising an endless belt adapted to engage 13. Feeding mechanism for sewing machines comprising an endless feed belt; and a presser foot, both belt and presser foot being pressed down upon the fabric being seamed, and both belt and presser foot having capacity for a rocking motion as the fabric passes beneath them.

14. Feedingmechanism for sewing-machines comprising an endless belt disposed in the rear of the needle of the sewing machine and in line with said needle in the direction of, feed; a presser foot forward of said belt; means for maintaining the belt and the presser foot in yielding pressure contact with the fabric being seamed and with alternating compensation of their vertical motions to allow for variations in the thickness of the fabric; and means for driving the belt.

15. Feeding mechanism for sewing machines comprising an endless belt; a presser foot; a single means for maintaining the belt and the presser foot in yielding pressure contact with the fabric being seamed; means permitting angular movement of the belt; and means for driving the belt.

16. Feeding mechanism for sewing machines comprising an endless belt; a presser foot; a single means for maintaining the belt and the presser foot in yielding contact with the fabric being seamed so that both have the capacity for rocking motion as the fabric passes beneath them; and means for driving the belt.

1'7. Feeding mechanism for sewing machines comprising an endless belt adapted to engage the fabric being seamed in the machine; means for supporting the belt with capacity for independent rocking movement, in operative connection with the presser bar of the sewing machine; a presser foot connected to the belt supporting means; and means for driving the belt.

18. Feeding mechanism for sewing machines comprising an endless belt adapted to engage the fabric being seamed in the machine; means 'for supporting the belt in operative connection with the presser bar of the machine and with capacity for up and down rocking movement; a presser foot connected to said supporting means with capacity to move up and down with the belt; and means for driving the belt.

19. Feeding mechanism for sewing machines comprising an endless belt; spaced wheels about which the belt is trained; a journal member for the wheels; means influential upon the journal member to maintain the belt with capacity for angular movement, in yielding contact with the fabric being seamed in the machine; and means for driving one of the wheels to move the belt.

20. Feeding mechanism for sewing machines comprising an endless belt; spaced wheels about which the belt is trained; a journal member for the wheels connected to the presser bar of the machine with capacity for independent rocking movement; means influential upon the journal member to maintain the belt in yielding contact with the fabric being seamed in. the machine; and means for driving one of the wheels to move the belt.

21. Feeding mechanism for sewing machines comprising an endless belt; spaced wheels about which the belt is trained; a journal member for the wheels connected to'the presser bar of the machine with capacity for up and down pivotal movement about the axis of one of said wheels; means influential upon the free end of said journal member to assist in maintaining the corresponding portion of the belt in yielding contact with the fabric being seemed in the machine; and

means for intermittently driving one of said wheels to move the belt.

22. Feeding mechanism for sewing machines comprising an endless belt; spaced wheels about which the belt is trained; a journal member for the wheels; a horizontal carrier member fulcrumed on one of the wheel axes; a presser foot pivotally connected to said carrier member; a shank member on the presser bar of the sewing machine whereto the horizontal carrier member is pivotally connected at a point intermediate the fulcrum wheel axis and the pivot axis of the presser foot, so that the belt and the presser foot can move up and down together to facilitate passage of cross seams in the fabric beneath them; and means for driving the belt.

23. Feeding mechanism for sewing machines comprising an endless belt; spaced wheels about which the belt is trained; a journal member for the wheels connected to the presser bar of the machine with capacity for up and down rocking movement; means influential upon the journal member to maintain the belt'in yielding contact with the fabric being seamed in the machine; means for driving one of the wheels to move the belt; and means for preventing rotation of the presser bar about its own axis and for maintaining the belt aligned in the direction of the feed.

24. Feeding mechanism for sewing machines comprising an endless belt; a drive and an idler wheel about which the belt is trained; a journal member for the two wheels; a horizontal carrier member fulcrumed on the drive wheel axis; a presser foot pivotally connected'to the carrier member; a shank member on the presser bar of the sewing machine Whereto said carrier member is pivotally connected at a point intermediate the drive wheel axis and the pivot axis of the presser foot so thatsaid belt and the presser foot can move up and down together to facilitate passage of cross seams in the fabric beneath them; a fixed vertically-slotted bracket engaged by a horizontal tongue projection of the shank member aforesaid; a guide member having a connection with the drive wheel axis, and a slotted upper portion slidingly engaging the tongue of the shank member to maintain the belt aligned in the direction of feed; and means for actuating the drive wheel to move the belt.

25. Feeding mechanism for sewing machines comprising an endless belt; spaced wheels about which the belt is trained; pressure means for sup-- porting the wheels with capacity to permit rocking movement of the belt about the axis of one the belt wheels as a fulcrum incident to passage of fabric therebeneath; means for driving the belt; and means whereby the slack of the belt may beregulated to permit passage of cross seams of difierent thicknesses beneath its center portion while the portions, of the belt at the wheels are maintained in contact with the fabric.

26. Feeding mechanism for sewing machines comprising an endless belt; spaced wheels about which the belt is trained; a. journal member for the wheels; means influential upon the journal member to maintain the belt in yielding contact with the fabric being seamed in the machine; means for driving the belt; and an axis pin whereon one of the wheels is mounted, said pin being rotatably adjustable in the journal member so that the slack of the belt may be regulated.

27. Feeding mechanism for sewing machines comprising an endless belt; spaced wheels about which the belt is trained: a journal member for the wheels: 9. horizontal carrier member fulcrumed on one of the wheel axes; a presser foot pivotally connected tosaid carrier member; a shank member on the presser bar of the sewing machine whereto the horizontal carrier member is pivotally connected at a point intermediate the fulcrum wheel axis and the pivot axis of the presser foot, so that the belt and the presser foot can move up and down together to facilitate passage of the cross seams beneath them; means for driving the belt; and adjustable spring means influential upon an arm extension of the horizontal carrier member to counteract, in part, the pressure of the presser bar and thereby correspondingly relieve the presser foot.

28. Feeding mechanism for sewing machines comprising an endless drive belt; a drive and idler wheel about which the belt is trained; a journal member for the two wheels; a horizontal carrier member fulcrumed on the drive wheel axis; a presser foot pivotally connected to the carrier member; a shank member on the presser bar of the sewing machine whereto said carrier member is pivotally connected at a point intermediate the drive wheel axis and the pivot axis of the presser foot so that said belt and the presser foot can move up and down together to facilitate passage of cross seams beneath them; a fixed verticallyslotted bracket engaged by a horizontal tongue projection on the shank member aforesaid; a guide member having a connection with the drive wheel axis and a slotted upper portion slidingly engaging the tongue of the shank member to maintain the belt aligned in the direction of feed;

a bevel gear on the drive wheel axis; an intermeshing bevel gear on a vertical shaft having journal support in a bearing on the guide member; an intermittently rotated vertical drive shaft journaled in the frame of the sewing machine; a sleeve having a universal connection with the first mentioned vertical shaft; and a key on the latter shaft slidingly engaging a slot in the sleeve.

29. Feeding mechanism for sewing machines comprising an endless'belt; spaced wheels about which the belt is trained; pressure means for supporting the wheels with capacity to permit rocking movement of the belt about the axis of either wheel as a fulcrum incident to passage of fabric therebeneath; and means for driving the belt.

30. Feed mechanism for sewing machines comprising an endless horizontal belt; spaced wheels about which the belt is trained; pressure means for supporting the wheels from above with capacity to permit rocking movement of the belt about the axis of either wheel as a fulcrum inand means for driving the belt.

31. Feeding mechanism for sewing machines comprising an endless belt with links having serrated edges to engage the fabric being seamed. in the machine; spaced wheels about which the belt is trained; pressure means for supporting the wheels with capacity to permit rocking movement of the belt about the axis of either wheel as a fulcrum incident to passage of the fabric therebeneath; and means for driving the belt.

32. Feed mechanism for sewing machines comprising an endless horizontal belt; spaced wheels about which the belt is trained; a pivotally supported presser foot in line with the belt; and pressure means permitting the belt to rock about the pivot of the presser foot and the latter to bodily rock about the axis of one of the belt I ported presser foot in line with the belt; and

pressure means permitting the belt to rock about the pivot of the presser foot and the latter to bodily rock about the axis of the belt wheel contiguous thereto.

34. Feed mechanism for sewing machines comprising an endless horizontal belt; spaced wheels about which the belt is trained; an arm fulcrumed on one of the wheel axes; a presser'foot pivotally connected to the outer end of the arm; and pressure means pivotally connected to the arm at an intermediate point.

35. Feed mechanism for sewing machines comprising an endless horizontal belt; spaced wheels about which. the belt is trained; a. presser foot in line with the belt; an arm to the end of which the presser foot is pivoted, said aim being fulcrumed on the axis of the belt wheel which is contiguous to the presser foot; and pressure means having a pivotal connection with the arm at an sure means for supporting the wheels and the presser foot with capacity to permit rocking movement of the belt either about the axis of the foremost of the two wheels or about the pivot of the presser foot incident to passage of fabric therebeneath; and means for driving the belt.

NORMAN V. CHRISTENSEN. CHARLES F. RUBEL. CLARENCE C.'SMITH. HAROLD J. LE VESCQNTE. 

